Apparatus for working on metal containers

ABSTRACT

An apparatus ( 10 ) for working on metal containers, especially suitable for high speed machines and intended for performing a sequence of operations on the metal containers themselves including a chain composed of a plurality of elements ( 12 ) linked in a succession and cooperating in simultaneous transporting and processing of metal containers.

TECHNICAL FIELD

The present invention relates to an apparatus for working on metalcontainers.

More in particular, the present invention relates to an apparatus forworking on metal containers to be used especially in high speed machinesthat operate in continuous and intended for performing a sequence ofoperations on the side surface of the metal containers themselves.

BACKGROUND ART

Metal containers subject to mechanical processes on said machinesbasically are those obtained in aluminium, alloys thereof, steel orother suitable materials with which containers for the beverage, foodfield or technical use are obtained; such metal containers, before beingsubject to the multiple operations in a sequence that modify the outerside surface thereof, can be subject to preliminary inner and/or outercoating and lithography of the outer side surface.

The metal containers processed on such types of machines preferably aresubject to different types of processes by plastic deformation called“necking” or “tapering”, that is, processes that partially change thegeometry of the container and the processes by plastic deformationcalled “shaping” which, on the other hand, globally change the geometry.The same metal containers can be subject to mechanical processes thatconsist in making recessed or projecting shaped impressions onpredetermined portions of the side surface of the containers themselves;said last processes are generally referred to with the term“embossing/debossing”.

As known, in machines that operate at high speed and in continuous, inorder to carry out the sequence of mechanical processes mentioned above,it is necessary to move the metal containers from one working tower tothe next one.

In said machines, the multiple working stations present wheels or“stars”, suitable for receiving the metal containers for transferringand processing, whose outer crown is shaped with suitable pockets basedon the diameter of the metal container to be processed; the transport ofsaid metal containers from one working station to the next one takesplace “at once”, that is, using the vacuum technique and suitablemechanical guides intended for conveying the metal containersthemselves.

A drawback of the conventional transport devices lies in the fact thatthey are unsuitable for moving complex shaped containers, such as thoseof the “bottle can” and/or “contour can” type, increasingly requested onthe market. In fact, such types of containers present complex shaping ofthe side surface that requires a high number of passages and a reducedcylindrical portion for gripping. The high number of passages and thus,of transfers “worsens” the traditional method of pick up with vacuumtechnique, since the use of guides for the direct conveying of the metalconveyors causes scratching that, if repeated, can cause damages to theside surface of the containers themselves.

Moreover, the reduced cylindrical portion and the shape of the containermakes the vacuum pick up, already “critical” for simple containers (ofthe “pop-can”) difficult; the use of such technique implies a certainpercentage of loss during the transfer from one working tower to thenext one.

A further drawback is that the current transport devices present limitsas regards the pick up strength that can be exerted on the containersand the movable mass.

A further drawback is that the traditional transport devices do notallow a high phase displacement between one working tower and the nextone, without inducing faults and causing the reject of the container orthe machine stoppage.

A further drawback is that such transport system is characterised bylong tooling before operations on a container of different format can becarried out.

DISCLOSURE OF THE INVENTION

The object of the present invention is to obviate the drawbacksdiscussed hereinabove.

More in particular, the object of the present invention is to provide anapparatus for working on metal containers which should ensure steady andsafe passage at high speed thereof, from one working tower to the nextone, irrespective of the mass moved without directly acting on the sidesurface of the metal container.

A further object of the present invention is to provide an apparatuswhich during the transport of the metal containers from one workingtower to the next one, should allow high phase displacement without anyconsequences on the process.

A further object of the present invention is to provide an apparatuseasy to disassemble and maintain.

A further object is to provide a transport apparatus that Is able tomanage different combinations of complexity of the product andproductivity, allowing the metal container to undergo even multipledifferent processes on the same tower.

A further object of the present invention is to provide the users with atransport apparatus suitable for ensuring high level of resistance andreliability over time, also such as to be easily and inexpensivelyconstructed.

This and other objects are achieved by the apparatus for working onmetal containers of the present invention, which comprises a chaincomposed of a plurality of elements linked in a succession andcooperating in simultaneous transporting and processing of metalcontainers.

BRIEF DESCRIPTION OF DRAWINGS

The construction and functional features of the apparatus for working onmetal containers of the present invention shall be better understoodfrom the following detailed description, wherein reference is made tothe annexed figures showing a preferred and non-limiting embodimentthereof, wherein:

FIG. 1 schematically shows a longitudinal section view of a portion ofthe apparatus for working on metal containers of the present invention;

FIG. 2 shows a front schematic front view of a portion of the apparatusof the invention;

FIG. 3 shows a schematic view of a layout of the apparatus of theinvention.

BEST MODE FOR CARRYING OUT THE INVENTION

With reference to the above figures, the apparatus for working on metalcontainers of the present invention, globally indicated with 10 at FIG.3, comprises a plurality of elements 12 shaped and connected to eachother, according to the methods detailed hereinafter, for defining aclosed chain and partially wound on multiple driving wheels 13 and idleor transfer wheels 15 of a high speed continuous machine not shown inthe figures. The idle or transfer wheels 15 have the function of“routing” the chain composed of elements 12 according to a path defineddepending on the design choices; some of the above idle wheels,moreover, define tighteners whose function is to keep the chain alwaystightened and compensate the irregularity thereof, due to dynamicstrains, due to the polygonal effect of the chain. The driving wheels13, on the other hand, are responsible for pulling the chain and aresubstantially at the machine working towers. In an alternativeembodiment the chain is movable using a friction rail.

Both the driving wheels 13 and the idle wheels 15 preferably are of thetoothed type so as to minimise the dynamic effects induced by theirregularity of the chain.

The elements 12, that compose the chain, are defined by a centralelement 12′ of basically annular shape that on the side surface presentstwo opposite shaped link-expansions 14 and 14′ suitable for allowing theconnection of one element 12 with the next one.

With particular reference to the preferred embodiment of the figures,the opposite shaped link-expansions 14 and 14′ of the elements 12 arerespectively of male and female type and are provided with a throughhole being directed rectangularly to the chain path, not indicated by anumerical reference in the figure, suitable for receiving the connectingor constraining means described hereinafter.

The male annular expansion 14, coaxially to the axial hole, seats atleast one anti-friction element 17 for example defined by a bearing,preferably of the rolling type; the function of such anti-frictionelement is detailed hereinafter.

An interface element 16, indicated in FIG. 1 with a dashed line as it isnot a part of the present invention and not an object of description, isseated coaxially to the single element 12 and internally to its centralelement 12′, suitable for receiving a metal container 18 and fortransporting it from a working tower to the next one of the machine forcarrying out the deformation processes on the side surface of the metalcontainer itself.

Each element 12 presents, preferably on the top front oriented to thebottom of the metal container 18, at least one optional angularreference element 20, for example defined by a projecting pin or a slot,with anti-rotation function towards the interface element 16 during thetransfer from one working tower to the next one. Such optional angularreference element 20 is used in the case of processes, such asembossing/debossing processes, that require the rotation and keeping ofthe angular position.

During the transfer of the metal container 18 from one working tower tothe next one, the part holder table 19 of each working stationinterfaces with the chain. The metal container inside the interfaceelement 16, when at the processing tool, located on a tool-holder table(not, shown in the figure), by the effect of the thrust exerted by apusher of the part-holder table 19, to which the interface elementremains integral, exits from the element 12 and moves in contact withthe processing tool (not shown in the figure). At the end of theprocess, the metal container 18 leaves the tool and reinserts into thechain at the same element 12 it had left.

In alternative embodiments the metal container 18 does not leave theelement 12 during the processing step, but it is the tool of thepart-holder table that with a translation motion approaches or retractsrelative to the metal container, interfacing therewith for the process.In this embodiment, therefore, the chain never leaves the container andfollows it in the processing step.

Each male shaped expansion 14 of an element 12 inserts in thecorresponding female shaped expansion 14′ of the next element 12. A pin22, inserted in the through holes of the shaped expansions 14 and 14′,defines a toroidal coupling or hinge between one element 12 and the nextone, such as to allow the uninterrupted winding of the chain relative tothe driving wheels 13 and to the idle wheels 15 of the machine.

With reference to FIG. 1, contact means with the driving wheels 13 andwith the idle wheels 15 of the continuous machine are arranged coaxiallyto the pin 22 and externally thereto, at the top front and at the bottomfront of the single element 12, on which the chain winds. Said contactmeans are defined by at least one further anti-friction element 24, forexample consisting of at least one bearing of the rolling type arrangedcoaxially to the pin 22 and by an optional damping element 26, forexample defined by one or more bushes of polymeric, metal or otherwisesuitable material, arranged coaxially and preferably externally to thefurther anti-friction element 24. Said contact means are arranged besidethe flanks of the central element 12′ and the pin 22 has a length of atleast the thickness of the two contact means in addition to thethickness of the central element and is locked at both ends.

The further anti-friction elements 24 have the function, together withthe anti-friction elements 17, of minimising the loss of mechanicalpower caused by the frictions and eliminate the need of a frequentlubrication of the chain, due to a potential contamination of theprocessed metal containers.

The optional damping elements 26 have the function of defining a supportinterface of the chain of element 12 relative to the continuoustransport and transfer elements of the machine, that is, the drivingwheels 13 and the idle wheels 15.

In fact, during the movement of the chain of element 12, which takesplace at a high speed, the damping elements 26 come in contact with thetransfer elements from one working station to the next one of thecontinuous machine; such contacts, which occur with a collision, are agenerating source of noise and vibration potentially dangerous ifprolonged over time.

In an alternative embodiment, said optional damping element 26 isarranged internally to the further anti-friction element 24.

In a further alternative embodiment, the optional damping element 26 isarranged on the driving wheels 13 and on the idle wheels 15 at thecontact zone with the element 12 of the chain.

The use of such damping elements 26, therefore, allows damping thecontact between the chain and the transfer elements, reducing the extentof the collisions and therefore reducing, the noise and the vibrationsinduced by the collisions themselves.

As can be noticed from the above, the advantages achieved by theinvention are clear.

The apparatus for working on metal containers of the present inventionprovides a transport system suitable for ensuring steady and safepassage of the metal containers, in particular of the bottle-can orcontour-can type, from one working tower to the next one, irrespectiveof the mass moved.

A further advantage is the elimination of the percentage of loss andscratching during the transfer of the metal containers themselves.

A further advantage is the fact that the chain of elements 12 managesthe transport of the metal containers and cooperates, simultaneously,with the processing of the same, does not affect the “fine” or accuratepositioning of the metal container on the working tower and thus theaccuracy and/or the quality of processing of the same is enhanced.

A further advantage of the invention is the fact that said apparatusallows the transport of the metal containers also with high angularphase displacements, between two contiguous working towers, withoutcausing damages to the container or machine stoppage.

A further advantage of the apparatus of the invention is the fact thatbesides the transport of metal containers it also has the advantage ofcooperating as power transmission means.

A further advantage of the apparatus of the invention is the fact thatthe same apparatus is easy to disassemble/assemble, flexible andre-configurable depending on the number and on the arrangement of thecontinuous machine wheels, and moreover, it is easy and convenient tomaintain.

A further advantage is the fact that the chain of bodies, as describedabove, allows containing the mass and the inertia moment, allowing theoperation thereof at a high speed even with unfavourable pitch-chain/no.of wheel teeth ratio; this along with the fact that the driving wheelsand the idle wheels can be suitably arranged, optimises the dynamicbehaviour and ensures longer useful life of the apparatus itself.

A further advantage is the fact that the closed structure of the chainof the apparatus of the invention along with the number of meshes of thesame in relation to the number of stations of the single working tower,easily allows the repositioning of the metal container on each workingtower, allowing the modulation of the number of operations required bythe complexity of the metal container itself.

Even if the invention has been described hereinbefore with particularreference to an embodiment thereof made by way of a non-limiting exampleonly, several changes and variations will appear clearly to a manskilled in the art in the light of the above description. The presentinvention therefore is intended to include any changes and variationsthereof falling within the scope of the following claims.

1. An apparatus (10) for working on metal containers, especiallysuitable for high speed machines and intended for performing a sequenceof operations on the metal containers themselves, characterised in thatit comprises: a chain composed of a plurality of elements (12) linked ina succession and cooperating in simultaneous transporting and processingof metal containers.
 2. The apparatus according to claim 1,characterised in that it comprises means for controlling the movementand the path of the chain.
 3. The apparatus according to claim 2,characterised in that the means for controlling the movement and thepath of the chain are defined by driving wheels (13) and/or idle wheels(15).
 4. The transport apparatus according to claim 3, characterised inthat the element (12) comprises a basically annular central element(12′), suitable for receiving an interface element (16) that receivesone metal container (18).
 5. The transport apparatus according to claim4, characterised in that the element (12) comprises a male and femaleshaped link-expansion (14 and 14′) in opposite positions relative to thecentral element (12′) and each provided with a through hole beingdirected rectangularly to the chain path.
 6. The transport apparatusaccording to claim 5, characterised in that the coupling between themale shaped expansion (14) of an element (12) and the female shapedexpansion (14′) of the contiguous element (12) is of the toroidal type.7. The transport apparatus according to claim 6, characterised in thatthe male shaped expansion (14) is annular and comprises, coaxially tothe through hole, at least one anti-friction element (17).
 8. Thetransport apparatus according to claim 7, characterised in that thetoroidal coupling between the contiguous element (12) comprises a pin(22) inserted coaxially to the through holes of the opposite shapedexpansions (14, 14′) of the element (12) themselves.
 9. The transportapparatus according to claim 8, characterised in that it comprisescontact means with the driving wheels (13) and with the idle wheels (15)of the high speed machine arranged at the ends of the pin (22) and atthe top front and bottom front of the single element (12).
 10. Thetransport apparatus according to claim 9, characterised in that thecontact means are arranged beside the flanks of the central element (12)and the pin has a length of at least the thickness of the two contactmeans in addition to the thickness of the central element and is lockedat both ends.
 11. The transport apparatus according to claim 10,characterised in that the contact means with the driving wheels (13) andwith the idle wheels (15) of the high speed machine comprise: at leastone anti-friction element (24) arranged coaxially to the pin (22);and/or a damping element (26) arranged coaxially to the anti-frictionelement (24).
 12. The transport apparatus according to claim 11,characterised in that the anti-friction element (24) comprises at leastone roller bearing.
 13. The transport apparatus according to claim 11,characterised in that the damping element (26) is arranged externally tothe anti-friction element (24).
 14. The transport apparatus according toclaim 11, characterised in that the damping element (26) is arrangedinternally to the anti-friction element (24).
 15. The transportapparatus according to claim 11, characterised in that the dampingelement (26) is arranged on the driving wheels (13) and/or on the idlewheels (15).
 16. The transport apparatus according to claim 11,characterised in that at least one angular reference element (20) ispresent on the surface of the central element (12′) of the element (12).17. The transport apparatus according to claim 16, characterised in thatthe idle wheels (15) define tighteners suitable for keeping the chainalways tightened and for compensating the irregularity thereof.